The present invention relates to a powder conveyor, particularly for coating powder, as well as a method for operating such a powder conveyor.
Powder conveyors serve in conveying powder, coating powder in particular, from a first powder reservoir to for example a second powder reservoir disposed downstream of the powder conveyor or a powder spray-coating gun or similar device for spraying coating powder disposed downstream of the powder conveyor. To this end, a powder conveyor usually comprises at least one pump, particularly a dense phase powder pump, whereby the pump normally comprises at least one conveyor chamber having a powder inlet valve and a powder outlet valve.
German patent application No. 10 2013 205 895.0, for example, relates to a powder conveyor comprising a dense phase powder pump, wherein the dense phase powder pump can be controlled by a control unit such that during a powder-conveying operating mode of the dense phase powder pump, coating powder is conveyed from a first powder reservoir to a second powder reservoir disposed downstream of the first powder reservoir, respectively to a downstream powder spray-coating gun.
In the powder-conveying operating mode of the dense phase powder pump, a portion of powder is alternatingly suctioned into the conveyor chamber through the open powder inlet valve while the powder outlet valve is closed and the portion of powder previously suctioned into the conveyor chamber through the open powder inlet valve is dispensed by the introduction of conveying compressed gas into the conveyor chamber while the powder inlet valve is closed.
In a flushing operating mode of the dense phase powder pump, however, either the powder inlet valve or the powder outlet valve is open while the other of the two valves is closed and whereby at the same time or after a delay, flushing compressed gas is introduced into the conveyor chamber.
On the other hand, the EP 1 551 558 A1 published document, for example, relates to a powder conveyor comprising a dense phase powder pump having a first conveyor chamber and a second powder conveyor chamber arranged parallel to the first conveyor chamber. The two conveyor chambers of this known prior art dense phase powder pump are each limited both on the intake side as well as the discharge side by a (mechanically operated) pinch valve arrangement.
The present invention is to address the task of further developing a powder conveyor of the type cited at the outset to the effect of being able to easily yet effectively detect a potential malfunctioning of the dense phase powder pump automatically. A corresponding method for operating such a powder conveyor is moreover to be specified.
This task is solved with respect to the powder conveyor as set forth in the specification and claims.